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Thread: 1250 maintenance questions?

  1. #1

    1250 maintenance questions?

    does anyone know yet if the procedures for adjusting the valves and checking cam timing is the same for the shiftcam motor as the 1200w motor? And will my cam tensioning tool, tdc tool and the cam timing tool from my 2015 work on the new motor? Also are the service intervals the same ? I plan to buy a new r1250rt in about a year and am curious to learn if i will still be able to do my own service.Thanks

  2. #2
    I have no idea as to the specific answers to your question, but would also venture that even if the procedure is different, if you can read the instructions for your current bike and do the maintenance then you will be able to read and/or see the instructions for the new bike and do that too. Maybe a new tool will be required but valve clearances are valve clearances. Measure and get them right.
    Paul Glaves - "Big Bend", Texas U.S.A
    "The greatest challenge to any thinker is stating the problem in a way that will allow a solution." - Bertrand Russell
    http://web.bigbend.net/~glaves/

  3. #3
    Registered User LFarling's Avatar
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    TDC tool should defiantly work.

    The cam chain tool should also work.

    And I would think the jig for the cam ends should work also.

    I been thinking about this and I think the cam returns and sits at the lower lift side of the dual cam profile. I also think the base circle for both cam profiles are the same only the lobe area would change and they do not come into play on valve checks as you are on the base circle of the cam to measure.

    I am thinking they will work but as has been reported the cam chain tensioner is not obtainable.

    If someone near me gets a 1250 I would love to find out and check it for them.
    Lee
    2017.5 R 1200 GSW

  4. #4
    Addicted to curves azgman's Avatar
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    I am not so sure the cam chain tool for the 1200 will work on the 1250. They have gone to a 3 piece "flat" cam chain and that means that it is likely the cam chain tension is different.
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  5. #5
    MOA #24991 Pauls1150's Avatar
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    Just a wag, but I agree that the tension is different; also, while the base circle has to be the same, would they actually wear at identical rates? Fer now (with zero experience on these), I'd say check both places and adjust the tighter one for correct clearance.

  6. #6
    Registered User pappy35's Avatar
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    Another WAG: The base circle area sees no load due to the clearance. When the bike is hot it close up a lot but it should never be in contact while running. So, no load means no wear to the cam at that location. Knowing that, if/when I own one, I'd probably still check it at both positions , assuming of course that it can be easily moved, because I can be anal about such things.
    '13 R1200RT 90th Anniversary Edition

  7. #7
    Registered User LFarling's Avatar
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    Quote Originally Posted by azgman View Post
    I am not so sure the cam chain tool for the 1200 will work on the 1250. They have gone to a 3 piece "flat" cam chain and that means that it is likely the cam chain tension is different.
    Maybe but I doubt it.

    I would bet the silver spacer would/could change to adjust for that if it did change. Make the spacer longer more tension, shorter less. I do not think the style of chain will make any difference at all.

    Now if the cam sprockets changed in size or the cam chain sprocket changed then yes it may have changed.

    Also I see no way the cam base circle will change from one cam lobe profile to the other. It just can not do that and keep the valve to shim space the same.

    Like I say would love to get to a new one and at least crack it and see what is what. I believe the tools will work. Just looking and comparing cam chain tensioners would be a little insight.
    Lee
    2017.5 R 1200 GSW

  8. #8
    Addicted to curves azgman's Avatar
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    I don't understand how the spacer would change the tension. You turn the cam chain tool until it slips at its preset torque value. Please 'splain this to me!
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  9. #9
    Registered User LFarling's Avatar
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    Quote Originally Posted by azgman View Post
    I don't understand how the spacer would change the tension. You turn the cam chain tool until it slips at its preset torque value. Please 'splain this to me!
    That ring would make the tool longer or shorter in the hole. So that would change where the tool started to make contact with the chain. At least that is what I think. I am sure I could be wrong.

    Has to be a reason for the spacer. I always assumed it was for when using the tool on another BMW bike you would use a different size spacer.
    Lee
    2017.5 R 1200 GSW

  10. #10
    wanderer
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    FWIW I had my R1200RS valves checked twice (over approx 35k miles) by the dealer, found no adjustment needed. The design is for wear to be complementing, largely self compensating. Great Engineering. I'm not saying checking is not needed...just that the issue is MUCH less than it was on the old airheads for instance.

    Unless engine maintenance is part of your joy of owernship, worrying about tools for this moot.

    Since my engine is well settled in now, I will not even think about it till I'm well over 70k miles.

  11. #11
    MOA #24991 Pauls1150's Avatar
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    Regarding that cam base circle:

    If your valve's adjustment is too tight, the follower rides on the base circle (the "flat") continually, and this will increase the wear there, and on the follower. (A drastic case would even prevent the valve from fully closing.) Which flat wears more quickly would then depend on which lobe the selector mechanism decides to spend more time on.
    How do they get tight?
    1) Improper shimming during setup or maintenance.
    2) Normal wear - as the valve seat gets pounded by the valve, and the backside of the valve hammers the seat, they get a little thinner and/or deform. This issue is typically more common on the exhaust side due to the higher temperatures there than on the intake; it hasn't been a "typical problem" for decades but can still happen.

    Several members on this forum have exclaimed "I set my valves Exactly to the factory spec and will not deviate from this", either because: 1) "The factory is always right", or 2) "Somebody on the web said that I'll get a quarter horsepower more out of it". (This is aside from the fact that anybody who can set valves can also show, at will, that setting them a teeny bit loose makes starting easier and lets the engine spin up AND down easier; it will also allow that adjustment to last longer. I won't get into how valve adjustment affects intake vacuum and throttle-body balance.)
    Since the clearance tightens up anyway with wear (on oilheads, Ks, and subsequent models), these folks are at greater risk.
    It's great that these items need much less maintenance these days (and we have yet to build up a history with this tech on the bikes), but that doesn't mean you can ignore it completely.

    I also agree that the chain tension itself likely is different, too: it's a completely different type of chain, which resists wear and twisting better than a single-run chain, and it's "probably" manufactured (an educated wag) with different clearances between its side plates and roller pins.

  12. #12
    Registered User LFarling's Avatar
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    Quote Originally Posted by Pauls1150 View Post
    Regarding that cam base circle:

    If your valve's adjustment is too tight, the follower rides on the base circle (the "flat") continually, and this will increase the wear there, and on the follower. (A drastic case would even prevent the valve from fully closing.) Which flat wears more quickly would then depend on which lobe the selector mechanism decides to spend more time on.
    How do they get tight?
    1) Improper shimming during setup or maintenance.
    2) Normal wear - as the valve seat gets pounded by the valve, and the backside of the valve hammers the seat, they get a little thinner and/or deform. This issue is typically more common on the exhaust side due to the higher temperatures there than on the intake; it hasn't been a "typical problem" for decades but can still happen.

    Several members on this forum have exclaimed "I set my valves Exactly to the factory spec and will not deviate from this", either because: 1) "The factory is always right", or 2) "Somebody on the web said that I'll get a quarter horsepower more out of it". (This is aside from the fact that anybody who can set valves can also show, at will, that setting them a teeny bit loose makes starting easier and lets the engine spin up AND down easier; it will also allow that adjustment to last longer. I won't get into how valve adjustment affects intake vacuum and throttle-body balance.)
    Since the clearance tightens up anyway with wear (on oilheads, Ks, and subsequent models), these folks are at greater risk.
    It's great that these items need much less maintenance these days (and we have yet to build up a history with this tech on the bikes), but that doesn't mean you can ignore it completely.

    I also agree that the chain tension itself likely is different, too: it's a completely different type of chain, which resists wear and twisting better than a single-run chain, and it's "probably" manufactured (an educated wag) with different clearances between its side plates and roller pins.
    Yes you surely get it.

    17.5 GS I checked valves at 600, 6000, and 12000. I changed all four exhaust valves. They were all tight from the 600 on. 3 were 34 and one was tight 35. They all sit at .37 now. I feel better and will check on them at the 18000.

    If you are sitting at the tight end of either valve range, IMHO I want to move to center or just below center, but not looser. And to have exhaust valves at the tight end, IMHO, it is very important to open those up.

    Yes I did forget the new chain design so that may be why the tensioner tool is unobtainable?

    But if the spring and size of the cam chain tensioner on the 1250 is the same as the 1200 then who knows?
    Lee
    2017.5 R 1200 GSW

  13. #13
    Addicted to curves azgman's Avatar
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    Quote Originally Posted by LFarling View Post
    Yes you surely get it.

    Yes I did forget the new chain design so that may be why the tensioner tool is unobtainable?

    But if the spring and size of the cam chain tensioner on the 1250 is the same as the 1200 then who knows?
    The engine engineers at BMW?
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